1. Field of the Invention
The present invention relates to a hand lever coupled to a shaft for operating the wedge-type breechblock of an artillery gun.
2. Description of the Prior Art
A charging hand lever is disclosed by D'Andrea in U.S. Pat. No. 3,362,292. This lever is solidly attached to a crank and located at the side of the bottom of the gun. When the breechblock is in a closing position closed and locked, then the charging hand lever is in a vertical location and is located near the plane to the rearward front of the breech ring. The breechblock is opened by turning the lever by 90.degree. downward. The lever is now in a horizontal position and protrudes far into the rear behind the bottom part. Even though the charging hand lever does itself not participate in the recoil motion of the weapon, it nevertheless represents a grave danger for the gun operator based on its horizontal position protruding into the operating area of the gun, while the breechblock is in open position.
1. Purpose of the Invention
It is an object of the invention to improve the structure of a hand lever for operating the wedge-type breechblock of an artillery gun in order to avoid the disadvantages set forth above and for effecting a rapid and safe breechblock motion.
It is another object of the invention to provide for an automatic release of the lever coupling with the shaft without the assistance of a person upon non-actuation for eliminating a possible safety risk to the gun-operating person.
These and other objects and advantages of the present invention will become evident from the description which follows.
2. Brief Description of the Invention
According to the present invention a hand lever system initiating the motion of the wedge-type breechblock of an artillery gun is provided. A shaft located at the bottom of the gun is connected with the breechblock. A drive connects the shaft with the hand lever and provides a coupling between shaft and lever upon actuation of the lever and otherwise automatically releases the coupling between shaft and lever resulting in dropping of the lever upon discontinuance of the actuation.
The hand lever comprises a loose socket wrench capable of being coupled to the shaft. The cooperating parts of lever and shaft are formed such as to provide upon operation of the lever a coupling with the shaft in both directions of rotation. Upon non-actuation of the lever the coupling automatically disengages and the charging hand lever falls down.
In one aspect of the invention, the shaft is provided with a locking head ending at about the lever of the breech ring. The head is parted by a two-step slot with prismatic surfaces coverging toward the side of the shaft and open at the ends. The head is capable of receiving a two-step bolt located at the free end of the hand lever. The cooperation of one pair of the head and the bolts results in a coupling between head and bolt and the other pair of steps is provided with measures for releasing the coupling.
In another aspect of the invention, the inner step of the head is formed as a roof shaped wedged groove with a stop dog increasing from the middle to both outward sides in height. A corresponding engaging dog of the outer step of the bolt engages behind the stop dog upon actuation of the hand lever to provide a coupling with the shaft. Furthermore, the engaging dog of the outer step of the bolt is formed by inclined planes of the inner step which meet at the middle of both sides in the shape of a roof. Each of the two inclined planes has protruding the head of a pretensioned spring bolt, which exert a pressure against the planar surface of the outer step of the locking head for placing the bolt in a middle position relative to the head.
In one feature of the invention the charging hand lever system comprises a drive coupling between the lever and the end of the shaft. The drive comprises a socket having a two-step bolting slot and each step has prismatic surfaces converging toward the side of the crank. Said slot is open toward the outside at both ends of the slot. A head at the free end of the lever has a two-step bolt with one step of the bolt and the locking slot providing a coupling between the hand lever and the shaft. The other step of the bolt and locking slot have means for releasing the coupling. The hand lever system can have about the same level as the breech ring of the gun.
The inner step of the locking slot is a roof shaped wedge groove with a stop dog which increase in height from the middle towards the two outsides for engaging the corresponding engaging dog of the outer step of the bolt. The engaging dog of the outer step of the bolt is formed by roof shaped inclined planes which converge in the middle. The head of the pretensioned spring bolt protrudes from each of the two inclined planes. The spring bolt heads exert pressure upon the inclined planes of the socket for placing the bolt in a middle position with regard to the slot of the socket. The width of the bolt is in general smaller than the clear width of the slot of the socket at the point of the locking position.
Furthermore, the hand lever is by its length, its weight, and its center of gravity as well as the distance and the pretension of the spring bolts and by the shape of the bolt and of the relative locking head slot adapted for automatically separating through the middle position from the coupling with the shaft.
Thus, the new hand lever system is not only simple to operate, but simultaneously it is to a large extent safe from accidents, since even when the gun operator does not remove the hand lever after use, it separates automatically and falls to the floor.
The invention accordingly consists in the features of construction, combination of elements, arrangements of parts, which will be exemplified in the device hereinafter described and of which the scope of application will be indicated in the appended claims.